簡介
本文說明如何將惡意IP地址或域名新增到思科郵件安全裝置(ESA)上的阻止清單中。
阻止惡意或問題發件人
阻止發件人的最簡單方法是將其IP地址或域名新增到ESA主機訪問表(HAT)中的BLOCKED_LIST發件人組。BLOCKED_LIST發件人組使用$BLOCKED郵件流策略，該策略的訪問規則為REJECT。
註:IP地址或域名來自傳送郵件伺服器。可以通過郵件跟蹤或郵件日誌捕獲傳送郵件伺服器的IP地址（如果未知）。
通過GUI阻止發件人
完成以下步驟，以便透過GUI封鎖傳送者：
- 按一下Mail Policies。
- 選擇HAT概述。
- 如果在ESA上配置了多個偵聽程式，請確保當前選擇了InboundMail偵聽程式。
- 從Sender Group列中選擇BLOCKED_LIST。
- 按一下Add Sender...
- 輸入要阻止的IP地址或域名。允許以下格式：
- IPv6地址，例如2001:420:80:1::5
- IPv6子網，如2001:db8::/32
- IPv4地址，如10.1.1.0
- IPv4子網，如10.1.1.0/24或10.2.3.1
- IPv4和IPv6地址範圍，例如10.1.1.10-20、10.1.1-5或2001::2-2001::10
- 主機名，如example.com
- 部分主機名，如.example.com
- 新增條目後，按一下Submit。
- 按一下「Commit Changes」以完成組態變更。
通過CLI阻止發件人
以下範例顯示如何透過CLI按網域名稱和IP位址封鎖傳送者：
myesa.local> listenerconfig
Currently configured listeners:
1. Bidirectional (on Management, 192.168.1.x) SMTP TCP Port 25 Public
Choose the operation you want to perform:
- NEW - Create a new listener.
- EDIT - Modify a listener.
- DELETE - Remove a listener.
- SETUP - Change global settings.
[]> edit
Enter the name or number of the listener you wish to edit.
[]> 1
Name: Bidirectional
Type: Public
Interface: Management (192.168.1.x/24) TCP Port 25
Protocol: SMTP
Default Domain: example.com
Max Concurrent Connections: 50 (TCP Queue: 50)
Domain Map: Disabled
TLS: No
SMTP Authentication: Disabled
Bounce Profile: Default
Use SenderBase For Reputation Filters and IP Profiling: Yes
Footer: None
Heading: None
SMTP Call-Ahead: Disabled
LDAP: Off
Choose the operation you want to perform:
- NAME - Change the name of the listener.
- INTERFACE - Change the interface.
- CERTIFICATE - Choose the certificate.
- LIMITS - Change the injection limits.
- SETUP - Configure general options.
- HOSTACCESS - Modify the Host Access Table.
- RCPTACCESS - Modify the Recipient Access Table.
- BOUNCECONFIG - Choose the bounce profile to use for messages injected on this
listener.
- MASQUERADE - Configure the Domain Masquerading Table.
- DOMAINMAP - Configure domain mappings.
- LDAPACCEPT - Configure an LDAP query to determine whether a recipient address
should be accepted or bounced/dropped.
- LDAPGROUP - Configure an LDAP query to determine whether a sender or recipient
is in a specified group.
[]> hostaccess
Default Policy Parameters
==========================
Maximum Message Size: 10M
Maximum Number Of Concurrent Connections From A Single IP: 10
Maximum Number Of Messages Per Connection: 10
Maximum Number Of Recipients Per Message: 50
Directory Harvest Attack Prevention: Enabled
Maximum Number Of Invalid Recipients Per Hour: 25
Maximum Number Of Recipients Per Hour: Disabled
Maximum Number of Recipients per Envelope Sender: Disabled
Use SenderBase for Flow Control: Yes
Allow TLS Connections: No
Allow SMTP Authentication: No
Require TLS To Offer SMTP authentication: No
DKIM/DomainKeys Signing Enabled: No
DKIM Verification Enabled: No
S/MIME Public Key Harvesting Enabled: Yes
S/MIME Decryption/Verification Enabled: Yes
SPF/SIDF Verification Enabled: Yes
Conformance Level: SIDF compatible
Downgrade PRA verification: No
Do HELO test: Yes
SMTP actions:
For HELO Identity: Accept
For MAIL FROM Identity: Accept
For PRA Identity: Accept
Verification timeout: 40
DMARC Verification Enabled: No
Envelope Sender DNS Verification Enabled: No
Domain Exception Table Enabled: Yes
There are currently 6 policies defined.
There are currently 7 sender groups.
Choose the operation you want to perform:
- NEW - Create a new entry.
- EDIT - Modify an entry.
- DELETE - Remove an entry.
- MOVE - Move an entry.
- DEFAULT - Set the defaults.
- PRINT - Display the table.
- IMPORT - Import a table from a file.
- EXPORT - Export the table to a file.
- RESET - Remove senders and set policies to system default.
[]> edit
1. Edit Sender Group
2. Edit Policy
[1]> 1
Currently configured HAT sender groups:
1. ALLOWSPOOF
2. MY_INBOUND_RELAY
3. WHITELIST (My trusted senders have no anti-spam scanning or rate limiting)
4. BLOCKED_LIST (Spammers are rejected)
5. SUSPECTLIST (Suspicious senders are throttled)
6. UNKNOWNLIST (Reviewed but undecided, continue normal acceptance)
7. (no name, first host = ALL) (Everyone else)
Enter the sender group number or name you wish to edit.
[]> 4
Choose the operation you want to perform:
- NEW - Add a new host.
- DELETE - Remove a host.
- POLICY - Change the policy settings and options.
- PRINT - Display the current definition.
- RENAME - Rename this sender group.
[]> new
Enter the senders to add to this sender group. A sender group entry can be
any of the following:
- an IP address
- a CIDR address such as 10.1.1.0/24 or 2001::0/64
- an IP range such as 10.1.1.10-20, 10.1.1-5 or 2001:db8::1-2001:db8::10.
- an IP subnet such as 10.2.3.
- a hostname such as crm.example.com
- a partial hostname such as .example.com
- a range of SenderBase Reputation Scores in the form SBRS[7.5:10.0]
- a SenderBase Network Owner ID in the form SBO:12345
- a remote blocklist query in the form dnslist[query.blocklist.example]
Separate multiple entries with commas.
[]> badhost.example.org, 10.1.1.10
注意：請記住提交從主CLI所做的所有更改。
意見